Apparatus and method for dynamic configuration of temperature profile in an integrated circuit

ABSTRACT

A method of dynamically configuring a temperature profile in an integrated circuit (IC). The method includes sensing temperature of the IC, configuring a reduced operating temperature range for the IC, and modulating at least one control mechanism to maintain the temperature of the IC within the reduced operating temperature range.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.11/277104 (Docket CNTR.2272), filed on Mar. 21, 2006

U.S. patent application Ser. No. 11/277104 (Docket CNTR.2272) claims thebenefit of, and incorporates by reference, U.S. Provisional ApplicationSer. No. 60/696703, filed on Jul. 05, 2005.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to integrated circuits, and moreparticularly to dynamic configuration of the temperature profile in anintegrated circuit which solves the problems associated with controllingthe temperature at which an integrated circuit operates.

2. Description of the Related Art

Many present day integrated circuits have provisions for controllingtheir operating temperature. For example, in a present daymicroprocessor, logic is provided therein to sense core operatingtemperature and to keep the operating temperature within some fixedrange typically by modulating the operating frequency and/or operatingvoltage of the part. Generally, an over-temperature threshold isprogrammed into a read-only register during manufacturing test and ifthe core temperature of the part exceeds this threshold duringoperation, control logic steps down the core frequency and/or coreoperating voltage in order to bring the core temperature back intoacceptable range.

The above technique for controlling temperature is disadvantageous fromthe perspective of a user or system integrator because it cannot bedynamically configured. For example, consider a systems integrator thatdesires to manufacture “green” systems, that is, systems that do notrequire what may be considered as undue amounts of energy.Alternatively, consider a laptop user who requires use of a laptopcomputer over a very long period of time without the capability torecharge. Moreover, consider a laptop user that is sensitive to heat anddoes not have the ability to situate their laptop computer in any placeother than their lap.

It is desired to enable the user or system integrator to dynamicallyconfigure the operating temperature profile in an integrated circuit,such as a microprocessor or the like.

SUMMARY OF THE INVENTION

An integrated circuit (IC) according to an embodiment of the presentinvention includes a temperature sensor, configurable temperatureprofile logic, at least one controller, and temperature control logic.The temperature sensor provides an operating temperature value. Theconfigurable temperature profile logic provides a configured operatingtemperature range. The temperature control logic has a first inputreceiving the operating temperature value, a second input receiving theconfigured operating temperature range, and at least one output coupledto each controller. The temperature control logic controls one or morecontrollers to maintain the operating temperature value within theconfigured operating temperature range.

The IC may include an interface mechanism that enables externalconfiguration of the configurable temperature profile logic. Theinterface mechanism may be any one or more of a system BIOS interface,an operating system interface and an application program interface.Profile protection logic may be provided to preclude configuration of anoperating temperature range at an unauthorized privilege level. Thecontroller may be any selected combination of a duty cycle controller, afrequency controller, a core voltage controller, a fan controller, and afunctional block controller. The configurable temperature profile logicmay be a register or the like, such as a machine specific register.

The IC may further include over-temperature threshold logic whichprovides a maximum operating temperature range to the temperaturecontrol logic. In this case, the temperature control logic controls eachcontroller to maintain the operating temperature value within either themaximum or the configured operating temperature range.

A microprocessor according to an embodiment of the present inventionincludes a core temperature sensor which provides an operatingtemperature, over-voltage threshold circuitry which provides a maximumoperating temperature range, configurable temperature profile circuitrywhich provides a reduced operating temperature range, one or morecontrollers, and temperature control circuitry. The temperature controlcircuitry operates the one or more controllers to maintain the operatingtemperature value within a selected one of the maximum operatingtemperature range and the reduced operating temperature range.

The microprocessor may include an interface mechanism that enablesaccess to the configurable temperature profile circuitry to specify thereduced operating temperature range. The interface mechanism may be aselected one of a system BIOS interface, an operating system interface,and an application program interface. The microprocessor may furtherinclude profile protection circuitry which precludes configuration ofthe reduced operating temperature range at an unauthorized privilegelevel. The one or more controllers may include any selected combinationof a duty cycle controller, a frequency controller, a core voltagecontroller, a fan controller, and a functional block controller.

A method of dynamically configuring a temperature profile in an ICaccording to an embodiment of the present invention includes sensingtemperature of the IC, configuring a reduced operating temperature rangefor the IC, and modulating at least one control mechanism to maintainthe temperature of the IC within the reduced operating temperaturerange.

The method may include programming via an interface mechanism, such asprogramming via a selected one of a system BIOS interface, an operatingsystem software interface and an application program interface. Themethod may include programming a register. The method may includemodulating either one or operating frequency and core voltage. Themethod may include modulating a rate of instruction execution. Themethod may include selectively activating a fan. The method may includeselectively activating a functional block of the IC.

BRIEF DESCRIPTION OF THE DRAWING(S)

The benefits, features, and advantages of the present invention willbecome better understood with regard to the following description, andaccompanying drawings in which the sole FIGURE is a block diagramillustrating dynamically controlling the operating temperature of anintegrated circuit according to one or more exemplary embodiments of thepresent invention.

DETAILED DESCRIPTION

The following description is presented to enable one of ordinary skillin the art to make and use the present invention as provided within thecontext of a particular application and its requirements. Variousmodifications to the preferred embodiment will, however, be apparent toone skilled in the art, and the general principles defined herein may beapplied to other embodiments. Therefore, the present invention is notintended to be limited to the particular embodiments shown and describedherein, but is to be accorded the widest scope consistent with theprinciples and novel features herein disclosed.

The present inventor has noted the situations noted above and similarscenarios where problems exist because of the fixed nature of presentday integrated circuit operating temperature controls. He has thereforedeveloped a system and method which enables dynamic configuration of thetemperature profile in an integrated circuit that solves the problemsassociated with controlling the temperature at which an integratedcircuit operates, as will be further described below with respect to thesole FIGURE.

The sole FIGURE is a block diagram illustrating dynamically controllingthe operating temperature of an integrated circuit (IC) 100 according toone or more exemplary embodiments of the present invention. In oneembodiment, the integrated circuit 100 is configured as amicroprocessor. The integrated circuit 100 has a core temperature sensor101 that provides a core operating temperature value T to temperaturecontrol logic 103. The temperature control logic 103 receives a “safe”or maximum operating temperature range TS from fixed over-temperaturethreshold logic 105, as described hereinabove. In contrast to presentday integrated circuits, the integrated circuit 100 also includesconfigurable temperature profile logic 107 that provides one or moreconfigured operating temperature ranges TR to the temperature controllogic 103.

The safe operating temperature range TS is generally determined as themaximum allowable temperature range for the integrated circuit 100 toachieve maximum performance without resulting in damage to any of thecircuitry on the IC. When the temperature T approaches or otherwiseexceeds a maximum temperature value or threshold indicated by TS, thetemperature control logic 103 takes the appropriate measures, describedfurther below, to reduce the temperature T to avoid damage orcatastrophic failure of the integrated circuit 100. It may be desired,however, to operate the integrated circuit 100 at a configuredtemperature range, as indicated by TR, for various reasons. Each“configured” temperature range is a temperature range that is reducedrelative to the safe or maximum temperature range TS. For example, theintegrated circuit 100 may be implemented to operate in a “green” systemfor environmentally sensitive applications or products in which theoperating temperature is reduced to conserve energy. Or, themanufacturer of the system incorporating the integrated circuit 100 maygenerally maintain the integrated circuit 100 at a reduced temperatureto extend the overall life of the system over time. Or, the user of thesystem incorporating the integrated circuit 100 may desire to reduceoperating temperature of the integrated circuit 100 to extend batterylife or to reduce the amount of heat radiated from the system.

The one or more configured operating temperature ranges TR can beestablished at various levels of configuration protection according todifferent embodiments. In one embodiment, profile protection logic 109is provided to preclude configuration of the one or more configuredoperating temperature ranges at unauthorized privilege levels. In anx86-compatible embodiment, such protection precludes modification of theconfigurable temperature profile logic 107 at levels other than thehighest protection level (e.g., ring 0 or operating system kernelprotection level). Such configuration may be used to enforce apredetermined reduced temperature range, such as a green system or areduced-temperature system designed for extended life. In alternativeembodiments, the present invention contemplates modification of theconfigurable temperature profile logic 107 by a user via any one or moreinterface mechanisms 110. The interface mechanisms 110 include, forexample, a system BIOS (basic input/output system) interface 111, anoperating system software interface 113, and an application programsinterface 115. External access is provided to enable modification by auser via any combination of the illustrated interface mechanisms 110.Other access techniques are contemplated as well. In one embodiment, theconfigurable temperature profile logic 107 is implemented as a machinespecific register in a microprocessor that is written at the highestprivilege level (e.g., privilege level 0) by operating system softwarevia the operating system software interface 113.

Responsive to inputs TS, TR and T provided by the fixed over-temperaturethreshold logic 105, the configurable temperature profile logic 107, andthe core temperature sensor 101, respectively, the temperature controllogic 103 controls the temperature of the integrated circuit 100 via oneor more control mechanisms 116. Accordingly, in various embodiments, thepresent invention contemplates one or more control mechanisms 116,including a duty cycle controller 117, a frequency controller 119, acore voltage controller 121, a fan controller 123, and other controllers125. The temperature control logic 103 controls the operatingtemperature within a selected operating range indicated by TS and TR.The TS input may be configured as the default operating temperaturerange for maximum performance, whereas the TR input is provided toreduce operating temperature for any of the reasons specified herein.

In operation, the duty cycle controller 117 modulates the rate at whichcontrol instructions are provided to execution logic (not shown) forexecution by the integrated circuit 100. For example, in a pipelinedevice such as a microprocessor, the duty cycle controller controls therate at which microprocessor instructions are issued for execution. Thefrequency controller 119 modulates core operating frequency of theintegrated circuit 100 and may be controlled in conjunction with a corevoltage controller 121. The core voltage controller 121 modulates corevoltage (e.g., “Vdd”) of the integrated circuit 100. A fan controller123 selectively activates (turns on or off) an attached fan or othercooling device (not shown). The “other” controller 125 contemplates anyother known or contemplated mechanisms for controlling temperature ofthe integrated circuit 100. For example, in a microprocessor embodiment,the other controller 125 includes logic for turning off certain logicfunctional blocks therein such as an optional L2 cache or any other oneor more optional functional blocks that are selectively activated orenabled to improve throughput but that are not essential for operation.

An advantage of the present invention is that operating thresholds cannow be dynamically configured for any one or more of a variety ofpurposes, such as to preserve battery life, to extend the overall lifeof the integrated circuit 100, or to reduce heat Operating theintegrated circuit 100 at reduced temperature generally extends the lifeand reliability of the integrated circuit 100 as understood by those ofordinary skill in the art.

Although the present invention has been described in considerable detailwith reference to certain preferred versions thereof, other versions andvariations are possible and contemplated. Those skilled in the artshould appreciate that they can readily use the disclosed conception andspecific embodiments as a basic for designing or modifying otherstructures for carrying out the same purposes of the present inventionwithout departing from the spirit and scope of the invention as definedby the appended claims.

1. A method of dynamically configuring a temperature profile in anintegrated circuit (IC), comprising: sensing temperature of the IC,configuring a reduced operating temperature range for the IC; andmodulating at least one control mechanism to maintain the temperature ofthe IC within the reduced operating temperature range.
 2. The method ofclaim 1, wherein said configuring a reduced operating
 3. The method ofclaim 2, wherein said programming via an interface mechanism comprisesprogramming via a selected one of a system BIOS interface, an operatingsystem software interface and an application program interface.
 4. Themethod of claim 1, wherein said configuring a reduced operatingtemperature range for the IC comprises programming a register.
 5. Themethod of claim 1, wherein said modulating at least one controlmechanism comprises modulating either one of operating frequency andcore voltage.
 6. The method of claim 1, wherein said modulating at leastone control mechanism comprises modulating a rate of instructionexecution.
 7. The method of claim 1, wherein said modulating at leastone control mechanism comprises selectively activating a fan.
 8. Themethod of claim 1, wherein said modulating at least one controlmechanism comprises selectively activating a functional block of the IC.